Avaliação da qualidade da água do rio Alegria (Medianeira/PR) através da determinação do IET e simulação do processo de autodepuração

Abstract

The Alegria River is located in the Medianeira town in Paraná’s west and is confluent from Itaipu Reservoir, besides it is the main source of Medianeira, being used by the Paraná’s Sanitation Company (Sanepar) to perform the abstraction of water to supply the city, which gives the amount of sewage treatment plant (ETP). The work aimed to characterize the concentration of organic matter and nutrients, nitrogen and phosphorus, launched by Medianeira town’s ETP. Throughout the spring season (Oct 1st to Dec 21th) and fortnightly, there were 4 campaigns for monitoring 5 sampling points in order to determine the potential impact that might be generated directly on water quality of the receiving body (Alegria River). There were also carried out physicochemical parameters analysis in the Alegria River, to make it possible to understand the processes’ dynamics. To identify the trophic level of the water body, it was used the model proposed by LAMPARELLI (2004) that proved to be an effective tool and of easy use in determining the trophic state index for lotic environments. The physicochemical analyzes were compared with the Brazilian legislation and some nonconformities were found in the CQO parameters, forms of nitrogen and phosphorus. With the analyzed data, it was possible to compare mathematical models. Two models were compared in order to characterize the purification process of organic matter in the river’s range from where the samples were taken off, the Streeper-Phelps’ model and an artificial neural networks’ model developed by SCHÜTZ (2014). Given the results, the Streeter-Phelps’ model and Neural networks shown effective to simulate the behavior of the river to the OD concentration.